Proper management and maintenance of ecosystems requires accurate knowledge of what is taking place in the ocean. To carry out long-term ocean observation, including of ecosystems, it is essential to strengthen observational infrastructure through the effective combination of various types of platforms such as satellites, ships, buoys, and underwater gliders. To achieve this, close international cooperation is a necessity.

We know that radionuclides have been emitted from the Fukushima Daiichi nuclear power plant into the sea, but how have they spread from there? Attempts are now underway to reproduce and predict their distribution using numerical simulation. After introducing one example of these, I will consider some coming challenges.
Selected Papers No.15

Red tide occurrences in the coastal zone increased dramatically with the spread of eutrophication during the period of high economic growth. The discovery that seaweed beds and seagrass Zostera beds enormous amounts of algicidal bacteria indicates that the land-reclamation and vertical shore protection projects carried out in this period, which reduced the seaweed beds and seagrass beds, also eliminated their red tide deterrence capability. The creation and restoration of seaweed beds and seagrass beds in shallow water ecosystems, and tidal flats should be effective as a red tide prevention strategies.